An investigation of the chemical strength of directionally solidified MgAl2O4-Y3Al5O12 eutectic ceramic materials at gas turbine conditions

Abstract

Nickel based alloys are mostly use in aircraft components such as nozzle, blade and heat shield in gas turbine engines. But the resisting temperatures of these alloys are limiting their applications, and cause environmental pollution with increasing energy costs. However directionally solidified eutectic oxide ceramics grown following melting, may eliminate these problems. In this study, the comparison of the production and hot corrosion resistance of eutectic structure MgAl2O4-Y3Al5O12 (MAS-YAG) produced by the directional solidification method and sintering magnesium aluminate spinel (MAS)-yttrium aluminium garnet (YAG) composite were compared for the same chemical composition. For this reason, volume, weight and microstructure (SEM) changes of the sinter and eutectic materials were observed. The flexural strength behaviour of sintered and eutectic MAS-YAG materials were investigated at room temperature and corrosive gas turbine condition at 1600°C. Corrosion results of directionally solidified MAS-YAG structure were better than conventional sinter ceramics for the same composition.